Automatic heating system



July 11, 1944. I G. L. CVHEASLEY 2,353,146

' AUTOMATIC HEATING SYSTEM Filed Aug. 14, 1941 2 Sheets-Sheet 1 INVENTOR.

[rm-don L fltdslq ATTORNEYS July 11, 1944. G. L. CHEASLEY I AUTOMATIC HEATING SYSTEM Filed Aug. 14, 1941 2 Sheets-Sheet 2 mk m MM M Z Z attains uo'romn rro HEATING Gordon L. Cheasiey, Westtleld, N. .3.

Application August lid, li dLfieria-l No. 4536,5364

2i @lainis. (@i. 23?-2) This invention relates to heating systems and more particularly to a combined air conditioning and hot water heating system having a common source of fuel and air supply and control means therefor.

' Combined air conditioning and hot water heating systems have been proposed heretoforewith the idea of using a single burner. An objection to this type of air and hot water heating system is that during the summer months an excessive amountol fuel is required to heat the larger furnace or heat exchange system by which the domestic hot water is provided. Other systems heretofore proposed include separate furnace and burner installations for the air heater and the hot water heater. The air heating system usually uses coal or oil as an economical fuel while the hot water heater may be provided with gas fuel. This type of installation requires a larger initial installation and equipment cost together with 9. higher fuel cost for the water heater.

One of the objects of the present invention; therefore, is to provide an air heating or conditioning and hot water heating system having low initial cost and economical fuel requirements.

Another object of the invention is to provide an air conditioning and hot water heating system in which the hot water heating may take place without any appreciable interference with the heating function of the air conditioning unit in winter operations and without affecting the tem= perature oi air or other cooling fluid medium cir collated through the air ducts of the unit in sum mer operations.

Still another olc-iect of the invention is to provide an air conditioning and hot water heating system having separate hmners and a coon arate heaters having a common source of fuel and air supply; also a control for selectively determining to which of two burners the supply of fuel and air should be delivered. I

I accomplish the foregoing and additional objects and features of my invention by providing two separate heat exchange units for the air heating system and the hot water heater, together with individual burners having in common an ignition transformer and a source of fuel and air supply including a motor driven pump and blower. The system is provided with'the usual temperature and safety controls normally included in properly installed air heating or conditioning systems, together with an automatic control unit, including a motor and switch means controlling the motor operating circuit, which is responsive to a demand for heat to be supplied to the hot water heater to command the supply of fuel and air for the hot water heater. The demand for heat is evidenced by a change in current flow condition in an aquastat circuit, as, for example,

by the closing of such circuit.

The command of the supply of fuel and air for the burner of the hot water heater is effected through actuation of a valve and a damper toy the motor of the automatic control unit which is energized in response to the closing of a switch built into the control unit or the motor thereof, the switch in turn responding to a change in.

current flow conditions in the aquastat circuit,

such as may he produced by the closing of such circuit, when the Water temperature has-dropped to a predetermined point. The valve and damper are returned to normalpositions by the unit when the water is heated to a predetermined tool and air supply together with means to regu= late the supply oi iuel an'd air so thatthe hot water can he maintained at or near a predeter mined temperature without any appreciable interierencc, with the normal operation oi the air heater.

temperature as is evidenced by a second change in current flow in the a uastat circuit, such as may ice produced by the opening of such circuit.

with a common the], and air supply together with a control and a common; ignition transformer whereby the some motor, pump, blower and ignition transformer. are used for each burner, and in which the 'capacity'oi these units need not be greater than that required by the larger 0i the turners'insteiled, and thereby eflecta' great new ing in parts. s y I Y An additional object of my invention is to provide a. novel dual burner installation mr two sep- The automatic control unit also controls the electric circuits to the ignition means of the two burners in accordance with the delivery of fuel and air thereto.

The dual iourner installation isso constructed that the burners can be easily installed and the burner for the. water heater disposed on that side of the air heater where it is most convenient to locate'the hot water heater. The flue for the hot waterheater is joined wlth the flue of the air heater at a point spaced from the heat exchange portions of the air heater sothat no heat transfer to the air ducts of the air heater'from thev hot water hea r is possible.

For a mor comple e understanding of the invention', reference will be had to the following detailed description which is to be read in connection with the accompanying drawings, in which: v

Fig. 1 is a sectional view in plan of the air conditioning and hot water heating system of my invention;

Fig. 2 is a view in vertical elevation with parts broken away to illustrate the details of the hot water heater;

Fig. 3 is a view in elevation of the burners as viewed from the right hand side of Fig. 2, with electrical connections and controls therefor shown diagrammatically; and

Fig. 4 is a sectional view of the three-way valve taken on line 4-'-4 of Fig. 1.

Referring to Figs. 1 and 2 of the drawings, I show for purposes of illustration a furnace i0.

It will be understood that the furnace Ill-may be I of any desired type and may be used for generating steam or heating water or air and may be provided with any desired type of burner l2. For purposes of illustration, I show the furnace ID as an air heating unit provided with a pressure atomizing gun type of oil burner. The water heater I4 is likewise provided with an oil burner iii of the ',same type, although it may be of a smaller capacity. 7

Common to the two burners i2 and [6 are a motor I8, a blower 20, a fuel pump 22 and an ignition transformer 10. The air from the blower is supplied through the tube 24 to the burner l2 and through a branch tube 28 to the burner I5.

The fiow of air to the burners is controlled by a damper 30 (Fig. 3), the operation of which will be hereinafter described, and individually adjustable airv flow controls 25 and 21 inthe burner tubes 24 and 26 respectively (Figs. 2 and 3) The controls. 25 and 21 have manually actuatable means 25 and 21 by which they can be adjusted.

The tube26 is universally mounted on the tube 24 so that the water heater l4 may be positioned at any one 'of a plurality of possible locations about the air heater I 0. The mounting comprises an annular element 3| suitably secured about an opening 33 to the side'of the tube 24. The element 3| is provided with an inwardly disposed annular flange 31 about which the vertical portion 23 of the tube 23 telescopes.

The hot air heater l0 comprises a fire box 32 surrounding by a double air jacket having an inner air space 34 and an outer air space 35. The combustion gases from. the fire box'32 pass through a cylindrical jacket interposed between the air spaces 34 and 35 before passage to the flue 38. The air heated in the spaces 34 and 35 is delivered through suitable ducts to the rooms or spaces to be heated.

The hot water heater I4 is shown for purposes of illustration as being of the fire tube type having a fire box 40 above which is provided a water ,tank 42 having a plurality of fire tubes 44 through and 66, which are normally used for hot air heaters and oil burners of the type illustrated. Since these controls are now conventional and may be purchased as units on the market, it is be- 'lieved unnecessary to illustrate the details there- To produce a circulation of air through the air jacket spaces 34 and 35 of the hot air furnace and the roomyor rooms to be conditioned, I provide a fan 5| (Fig. 1) driven by a motor 52. The motor 52, is so connected in the electrical control circuit that it may be independently controlled fer summer use in connection with an air cooling unit or for such purposes ,as causing circulation of filtered air through the rooms. For this purpose I provide a circuit connection 53 across the electric wires 54 and 55 which is controlled by a manual switch 56. Where an air cooling or dehumidifying apparatus is used dur-- in summer weather, suitable connections such as 51 are provided whereby the motor 52 can be automatically controlled in conjunction with such apparatus. The system is provided with the usual his limit temperature and circulating fan control 60 through which the other bumer-controls areconnected at 62. The high temperature limit switch rooms to be heated when the temperature of which pass the combustion gases from the combusti'on chamber 45. r

The products of combustion from the hot water heater M are conducted through a fine 45 to the flue 33. The flue 38 is connected with the shown diagrammatically several controls 50, 64

the air within the dome of the heater reaches a predetermined degree. The stack control 64 provides the usual safety features such, for example, as shutting ofi the pump and blower motor l8 and opening the circuit to the high voltage transformer 10 should the fuel and air mixture fail to ignite upon the lapse of a predetermined interval following an attempt to start the burner. Connected to the stack control and con-- trolled therethrough is a common type of room thermostat 53 which'responds to room temperature to normally determine the starting and stopping of the main burner l2.

Leading from the stack'control 64 are wires 33 and 69 which are connected to a high voltage transformer 10. The connections 1| and 12 'on the high voltage side of the transformer 10 :are connected to the ignition points 14 of the main burner I2 and .the ignition points 15 of the burner I 6. ,'To control the energization of the points 14 and 15 I provide a snap action switch 16 which is adapted to engage one or the otherof the stationary contacts 11, 18 to determine which of the two sets of points 14 and 15 are to be energized, The operation of the switch 16 in its cooperation with the burner controls will be described hereinafter.

A wire extending from the wire 63 and a third wire 3| connected to the'stack thermostat 34 are connected to the blower motor I 8. By these connections it will be seen that the blower motor l8 and the ignition points 14, 15 are controlled through the thermostat controls 54 and- 56, subject, of course, to the high temperature limit switch 62.

interposed in the control system to the bumers heretofore described is my novel automatic control unit for the operation of. the dual burners. When heat is required for the hot water 'veryshort period of time is required to raise the temperature in the hot water boiler because of the heating capacity of the heater it. A diversion of the fuel and air supply from th burner I2 during operation thereof does not affect apbecause of the residual heat accumulated in the walls of the heater, after a short period of burner preciably the heating function of the heater It lit operation. This residual heat is normally suflicient to maintain a supply of heat for circulation by the fan driving motor 52 for the period dur-" ing which the fuel and air supply is diverted. This is further apparent since, during normal operation of an air heater; the operation of the burner thereof in response to a continuous demand for heat is intermittent. The heat, for

example, supplied by the burner I2 when it exceeds a. predetermined amount actuates the high limit control switch 62 to cut off the burner I2 while the fan 5! is maintained in operation until a large part of the heat in the furnace is dissipated and the temperature reduced below a predetermined value; Thus a diversion of the fuel and air supply to the heater for the short intervals required by the hot water heater does not, in accordance with my invention, rinterfere materially with the heatingfunction of the air I heater It.

Referring more particularly to Fig. 3 of the drawings, the novel control unit 85 comprises a motor 84 of known type which is provided with built in reduction gearing and switches. Since this type of motor is well known, the details thereof have not been illustrated and it is vhelieved require no discussion other than that the motor is adapted to be energized, through the intermediary of built-in switch means, not

shown, in response to the closing of a two-wire thermostat circuit to drive the shaft 82 thereof through 180 and then stop. The motor is also adapted to be energized again, through the intermediary of switch means, not shown, when the thermostat circuit opens, and thereupon drives the shaft 32 through another 180. The. motor is provided with a manual switch 83 which takes precedence over the thermostat connections, that is to say/, the switch 83 (Figs. 2 and 3) when iri vertical or No. 2 position connects the motor for automatic operation. When in No. 1 position it connects the motor the same as when the thermostat circuit is closed and when in No. 3 position it connects the motor the same as when the thermostat circuit is open.

The power for operating the motor 84 for my control unit 85 is supplied through the lead wires a 180 turn, the energization of the motor being effected through the intermediary of the builtin switch means which responds to the change of current flow condition in circuit connections 98, I39. L

Mounted on the shaft 82 is a cam "it which is provided with diametrically disposed raised portions It'll and H32. Associated with the cam IIlIl isa switch arm M which is pivoted at 05 and biased by a spring tilt to engage the surface of the cam Hill. While the arm IM is engaged by the raised portion Hit or I02, the movable contact 'IIIi on the arm Hit is adapted to engage a stationary contact I I2.- The engagement of the contacts Ho and II2 completes a, circuit from the high temperature limit switch connection 62 through a wire Ht, contacts IIII, H2; a flexible connection H6 and a wire H8 to the stack control GE. The opening of the contacts H0, H2

interrupts the circuits to the stackcontrol 64 and thereby the circuits to the burner motor I8 and the highvoltage transformer 10."

Theinterruption of the circuit to the blower motor It by the initial operation of the-shaft 82 deenergizes the motor It until the cam I00 has revolved through, 180, During this movement acrank arm I2Il carried by the shaft is moved from one position to another position diametrically opposite thereto. The'crank arm I20 is connected to a rod I22 which in turn is connected to one corner of sector I24 which ispivoted at a second corner I26. A third corner of the sector is pivotally connected to a rod I26 which in turn is connected to the arm I28 of the damper 30.

The connecting rod I22 is provided with a pair of adjustable lugs I30 and I32 which are adapted the crank arm I20 from the downwardly extend- 54 and 55 which are in turn connected re'spectively to the wires 86 and 81. The wires 86 and 81 are connected through a low -voltage transformer 90 and the wires 9i and 92 to the ter minals 93, 96 ofthe motor 84.

. An aquastat 95 whichis associated with the water heater H (Figs. 1, 2 and 3), is provided with terminals I, 2 and 3, I andii of which are connected by the wires S8 and 99 to the terminals 96, 91 of a switch (not shown) which closes the energizing circuit of the motor 84. The terminals I, 2 and '3 are connected by wires 88a, 99a and 9% respectively to the usual three control connections between the room thermostat 66 and the stack control 64. These connections provide parallel control of the blower motor It by the thermostat 66 and aquastat 95. The change of current flow condition in circuit connections 98,

ing position to an upwardly extending position, the damper 30 is moved from a lower position indicated in broken lines (Fig. 3) to a horizontal position closing off the air supply to the tube 26. During this movement, of the shaft 82 the lug I32 on the rod I22 is adapted to engage the switch arm I34 and when it has movedpas't the horizontal the spring I38 will snap the arm upwardly for engagement with the stationary contact I8.

This operation breaks the engaged relation' of contactIG, 'Il'ofrthe circuit to the ignition points ignition points.

The movement of the shaft 82 also-controls the fuel supply to the burners I2 and I6. In the operation juit described a three-way valve I40, the. stem I of which is connected to the shaft I5 and closes contacts I6, I8 of the circuit to the 82 (Figs. 1, 2 and 4) ,is actuated to close the'delivery connection I42 to the burner I6 and open theconnection I to the burner I2. The third connection IE6 communicates with the discharge side of the pump 22.

:To summarize the operation of the dual burn- I ers it may be assumed that the system is under winter operations. 3 is shown for hot water heating, it will be assumed that the hot water aquastat has called Since the illustration in Fig;

for heat and the burner I6 is now in operation. When the aquastat contacts are opened in response to a rise in water temperature, the motor 84 will be energized to drive the shaft 82 through 180 whereby th cam portion I 02 will permit the switch arm I04'(Fig. 3) to move clockwise under the tension of the spring I06 to disengage contacts H0, H2. The disengagement of these contacts deenergizes the burner motor I8 thereby discontinuing the supply of fuel and air; The continued operation of the motor 84 raises the crank arm I20 causing the switch contacts 18, TI to disengage and beforethe motor 84 is deenergized to cause the contacts 18, I8 to close due to the toggle action of the spring I36. This switch operation interrupts the ignition circuit to the ignition points and completes the circuit to the ignition points 14 preparatoryto the initiation of the main burner I2. The raising of the crank arm I to the upper position moves the damper 30 from the positionshown in Fig. 3 to a position closing the communication from the blower 20 to the tube 26. The valve stem I being revolved 180 closes the connection I42 and opens the connection I44. At the end of the operation of the motor 84 the cam portion IOI is adapted to move the arm I04 counter-clockwise and effect the reengagement of the switch contacts H0, H2. By the reengagement of these contacts the control circuit through the stack control 64 is conditioned for reenergization of the blower motor I8. Should the room thermostat 66 call for additional heat the motor I8 and the ignition points 14 will then be energized,

whereby the burner I2 will assume operation. Should the roomithermostat 66 not be in a position to call for heat when the control motor 84 returns the controls to their normal connections, the system will remain idle until either the room thermostat 86 or, the aouastat 95 is actuated.

From the foregoing description it will be clear that when the aquastat contacts are closed in response to a lowering of the hot water temperature, the control unit 85 will respond to disconnect the control-circuit to the motor' I8 and the transformer I0, change the positions of the fuel valve I40 and the damper 30 to'direct fuel and air to the burner I6, and reconnect the control circuit to the motor I8 and the transformer I0. Where the term "air conditionin and hot water heating system is used in this specification and the appended claims, it is to be understood as including besides those systems wherein air. is merely heated and then circulated through a dwelling or other space, systems wherein air or another fluid medium is either humidified or dehumidified along with heating or cooling of suchfluid prior to its introduction into the space to be affected thereby.

While I have shown and described but one embodiment ofmy invention, I recognize that many embodiments and modifications thereof are possible without departing from the spirit thereof. It should therefore be understood that the form of the invention herein illustrated and described is intended to be illustrative only and not as limiting the scope thereof.

I claim:

1. In an air conditioning and hot water heating system for supplying heat to a dwelling or other space to be heated and also supplying hot water as needed, a fluid heater and a hot water heater each having its own burner, means common to the heaters to supply fuel and air to the perature of the space the atmosphere of which is to be heated to normally control the supply of fuel and air to the burner of the fluid heater, and means responsive to a drop below a predetermined value in the temperature of the water heated by the hot water heater to command the supply of fuel and air for the burner of the hot water heater to the exclusion of said fluid heater.

2. In an air conditioning and hot water heating system for supplying heat to a dwelling or other space to be heated and also supplying hot water as needed, a fluid heater and a hot water heater each having its own burner, a pump and a blower common to-the two burners, a motor to drive said pump and said blower, a valve and a damper to determine to which of the burners the fuel and air is supplied, means responsive to the temperature of the space the atmosphere of which is to be heated to normally control the operation of said motor to supply fuel and air to the burner of the fluid heater, and means responsive to a drop below a predetermined value in the temperature of the water heated by the hot water heater to position the valve and damper so as to direct the supply of fuel and air to-the' burner of the hot water heater to the exclusion of said fluid heater.

3. -In an air conditioning and hot water heat- "lng system forsupplying heat to a dwelling or is to be conditioned to normally control the energization of the ignition points of the burner of the fluid heater, and to control said motor to supply fuel and air to said burner, and means responsive to a drop in the temperature below a predetermined value of the water of the hot water heater to connect the ignition points thereof for energization and to positionithe valve and the damper so as to direct the supply of fuel and air to the burner of the hot water heater to the exclusion of said fluid heater.

4. In an air conditioning and hot water heating system, a fluid heater and a hot water heater each having its own burner, a motor, a pump and blower common to said burners and driven by said motor, a valve and a damper to determine to which of the burners the fuel and air is supplied, means responsive to the temperature of the spa-cethe atmosphere of which is to be conditioned to normally control the operation of said motor to supply fuel and air to the burner of the fluid heater, means responsive to a drop below a predetermined value in the temperature of the water heated by the hot water heater to position the valve and the damper so as to direct hot water heater to the exclusion of said fluid heater, a switch to control said motor, and means bumers'thereof, means responsive to th tem- 76 to hold said switch. open during the changing of the valve and damper positions. 5.- In an air conditioning and hot water heating system, a fluid heater and a hot water heater each having its own burner, electrical ignition points for each burner, a motor, a pump and a blower common to and driven by said motor, a valve and a damper to determine to which of the burners the fuel and air is supplied, means retube associated with sesame sponsive to the temperature of the space the atmosphere of which is to be conditioned to nor-'- mally control the energization of 1e ignition points of the burner of the fluid heater and to control the operation of said motor to supply fuel and air to said burner, means responsive to a drop below a predetermined value in the tem-= perature of the water heated by the hot water heater to connect the ignition points of the burner therefor for energization and to position the valve and damper so as to direct the supply of fuel and air to the. burner of the hot water heater to the exclusion Tof said fluid heater, a switch to control said motor, and means to hold said switch open during the changing of the temperature of the water of the hot water heater to move said damper to a position to divert substantially. all of the supply of air through the the burner of the hot water heater.

'7, In an air conditioning and hot water heating system, a fluid heater and a hot water heater each having its own burner, a valve to determine to which of the burners fuel will be suppliedQa blower, an airtube for each burner, a damper to heater, a circulation blower motor for the fluid heater, means responsive to the temperature in said fluid heater to control said blower motor, and means responsive to a dro below a predetermined value in the temperatureof the water heated by the hot water heater to command for a short interval and to the exclusion of the fluid heater the supply of fuel and air for the burner of the hot water heater, and said fluid heater having a residual heat capacity. such as to normally maintain said blower motor in operation for at least a substantial portion of the usual interval during which fuel and air are diverted to the burner of the water heater [and such diversion interrupts the operation or" the fluid heater.

10. In an air conditioning and hot water heating system for supplying "heat to a dwelling or other space to be heated and also supplying hot water asneeded, a fluid heater and a hot water heater each having its own burner, means common to the heaters to supply fuel and air to the burners thereof, means responsive to the temperature of the space the atmosphere of which is to be heated to normally control the,

supply of fuel and air to the burner of the fluid heater, a circulation blower motor for the fluid heater, means responsive to the temperature in selectively control the flow of air through said tubes, means, tonormally'maintain the damper in position to direct airthrough the tube associated with the burner of the fluid heater, and, means responsive to a drop below a predetermined value in the temperature of the waterof the hot water heater to position said valve and said damper to direct the flow of fuel and air to the burner of the hot water heater to the exclusion of said fluid heater. i

8. In an air conditioning and hot water heating system, a. burner to provide heat for space heating purposes, another burner for a hot water heater, a valve to determine to which of/the burners fuel will be supplied, electrical ignition points for each burner, a switch to control selec- 4 tively the energization of said points, a source of air supply, an air tube for each burner, a damper toselectively direct air througlrsaid tubes, means normally to maintain the damper in position to direct air through the tube associated with the burner for space heating purposes, and means responsive to a drop below'a predetermined value in the temperature of the water of the hot water heater to move said switch, valve and damper so as to connect the ignition points of the burner of the hot water heater for energization and to direct the flow of fuel and air thereto to the exclusion of said space heating burner.

9. In an air conditioning and hot water heating system for supplying heat to a dwelling or other space to be heated and also supplying hot water as needed, a fluld'heater and a hot water heaterv each having its own burner, means common to-the heaters to supply fuel and air to the burners thereof, means responsive to the temperature of the space the atmosphere of which is to be heated to normally control the supply of fuel and air to the said fluid heater to control said blower motor,

separate means to control the blower motor during hot weather, and means responsive to a drop below a predetermlned'value in the temperature of the water heated by the hot water heater to command for a short interval and to the exclusion of the fluid heater the supply of fuel and air for the burner or the hot water heater, and said fiuid heater having a residual heat capacity such as to normally maintain said blowergmotor in operation for at least .a. substantial portion of the usual interval during which fuel and air are diverted to the burner of the water heater and such diversion interrupts the operation of the fluid heater.

11. A pair of burners, the first of said burners being adapted to supply heat for short periods and the second of said burners. to normally supply heat for longerperiods, a common source of fuel and air supply for said burners, a valve and a damper to control the flow of fuel and air to one or the other of said burners, a motor, and means responsive to a demand for heat from said first burner to energize said motor to move the damper and valve to positions for directing fuel and air to said first burner, and responsive to a satisfaction of said demand to again energlze said motor to move the damper and valve toi ositions ifor directing fuel and air to said second burner;

12. A pair of burners, the first, of said burners being adapted to supply heat forshort periods and the second of said burners to normally supply heat for longer periods, a common source of fuel and air supply for said burners, avalve and a damper to control the flow of fuel and. air to one or the other of said burners, elec- 'trlcal ignition points for each burner, a switch to control selectively the energization of said points, means including a motor adapted when energized to move said valve and said damper to change the fuel and air supply from one burn er to the other burner, means actuated by said the ignition points of said one burner and conburner of the fluid motor during energlzation thereof to disconnect nectforenergization the ignition points of said other burner, and means responsive to a demand for heat from said first burner to energize said motor to move the damper and valve to positions for directing fuel and air to said first burner, and responsive to a satisfaction of said demand to again energize said motor to move the damper and valve to positions for directing fuel and air to said second burner. Y

13. A pair of burners, the first of said burners being adapted to supply heat for short periods and the second of said burners to normally supply heat for longer periods, a motor, a pump and a blower driven by said motor to supply fuel and air from a common source to said burners, a valve and a damper to control selectively the fiow of fuel and air respectively, a second motor, means responsive to a demand for heat from said first burner to energize said second motor to move said valve and said damper from positions directing fuel and air to said second burner to positions for directing the fuel'and air to said first burner, and means to insuredeenergization of said first mentioned motor during the changing of the valve and damper positions. ,14. A pair of burners, a blower arranged'as a common source of forced air supply to supply air for said burners, an air tube to conduct air to one of said burners, another air tube to conduct air to the other of said burners, and a universal connection for one of said tubes whereby one of the burners may be located at any one of a plurality of positions with respect to the other of said burners.

15. A pair of burners, the first of said burners being arranged to supply'heat for short periods and the second of said burners to normally supply heat for longer periods, a common source of air supply forthe burners, including branched tubes, a damper adaptedfor movement to two different positions to direct the flow of air through one or the other of said tubes, a control including a motor adapted to rotate its shaft a predetermined amount each time the motor is energized, means operatively to connect said damper to said motor shaft whereby said damper is moved from one to the other of said positions whenever the motor is energized, and means responsive to a demand for heat from saidfirst burner to energize said motor to move the damper to a position for directing the fiow of air to said first burner, and responsive to a satisfaction of said demand to again energize said motor to move the damper to a position for directing the fiow of air to said second burner.

16. In a heating system comprising two heaters each having a burner, means to normally control the supply of fuel and air for delivery to one of the burners, means having preference over the first mentioned means to control the supply of fuel and air for delivery to the'other of the burners, a main fiue, a branch fiue for each heater communicating with said main fiue, temperature responsive means associated with said main flue, and safety control means associated with said main'fiue and operable after the temperature reading of said temperature responsive means has remained below a predetermined value for a predetermined interval of time to cut off delivery of fuel and air to both of said burners.

17. In an air conditioning and hot water heating system for supplying heat to a dwelling or other space to be heated and also supplying hot water as needed, a fiuid heater and a hot water heater each having its own burner, a pump and the temperature of the space the atmosphere of which is to be heated to normally control the operation of said motor to supply fuel and to the burner of the fiuid heater, second means having preference over the first mentioned means and responsive to a drop below a predetermined value in the temperature of the water heated by the hot water heater to position the valve and damper so as to direct the supply of fuel and air to the burner of the hot water heater, and means responsive to the operation of said second means to energize said motor.

18. A control unit for controlling the fuel supply for a heating system having two bumers, the first burner to provide heat for short periods of demand and the second burner normally to rovide heat for longer periods, and'a common source of fuel for said burners; said- -control unit comprising a valve to control the fiow of fuel to said burners, said valve being positioned normally to deliver fuel to said second burner, a motor to control said valve, and means responsive to a demand for heat from said first burner to energize momentarily said motor to move said valve,to a position to deliver fuel to said first burner to the exclusion of said second burner, and responsive to a satisfaction of said demand to energize momentarily said motor to return said valve to the first men-'- tioned position.

19. A control unit for controlling the ignition for a heating system having two burners, the first burner to provide heat for short periods of demand and the second burner normally to provide heat for longer periods, and each burner having an individual ignition device; said control unit comprising first and second stationary contacts, the first contact for connection to the ignition device of the first burner and the second contact for connection to the ignition device of the second burner, a movable con-' tact, an arm for the movable contact, a pivot for said arm, a toggle to move said arm with a move said arm to effect closure of said movable I contact with said first contact, and responsive to a. satisfaction of' said demand to energize said motor to return the said arm to effect engagement of said movable contact with said second contact.

20. A control unit for controlling the fuel supply and the ignition for a heating system having two burners, the first burner to provide heat for short periods and the second burner normally to provide'heat for longer periods, a common source of fuel for said burne'rs, and an individual ignition device for each burner; said control unit comprising a valve to control the flow of fuel to said burners, said valve being positioned normally to deliver fuel to said second burner,

- the first burner and the second contact for cona blower common to the two burners, a motor to nection to the ignition device of the second burner, a movable contact normally engaging said second contact, a motor to control said valve and said movable contact, and means reburner to energize the motor to move said movable contachto engage said first contact and to move said valve to a position to' deliver fuel to said first burner to the exclusion or said second burner, and responsive to a satisfaction of said demand to energize momentarily said motor to return said movable contact and said valve to their normal positions.

g 21: A control unit for controlling the fuel sup-- ply, the ignition and the air supply for a heating system having two 1)}1111618, the first burner to provide heat for short periods and the second burner normally to provide heat for longer periods, common sources of fuel and air for said burners, and an individual ignition device for each of said burners; said control unit comprising a valve to control the fiow of fuel to said burners, said valve, being normally in a position to deliver fuel to said second burner, a 20 I I 2,868,14 sponsive. to a" demand for heat from said first first contact for connection to the ignition de-' vice of said first burner, a second contact ior connection to the ignition device of the second burner, a movable contact normally engaging a position to direct the supply of air to said first burner, and responsive to.a satisfaction of said demand to energize said motor to return said valve, said movable contact and said damper to their normal positions.

GORDON L. CHEASLEY. 

